Although an outside air temperature range to which a conventional wind turbine generator is applied is generally −10° to +40°, in recent years an installation region of the wind turbine generator is spread to upland and a cold region. In such a case, the outside air temperature is spread to a range of −30° to +40°. Therefore, it becomes more important to control the temperature of devices in a nacelle such as a gear box, a main bearing, a generator, a transformer, and an inverter.
As a temperature control system, an oil piping system provided in a blade pitch system, the gear box, the main bearing, or the like has a heater, while a cooling water piping system such as an inverter has a cooler, respectively, and their temperatures are controlled within predetermined temperature ranges (see Patent Citation 1 for example).
A hull of the nacelle is formed with an air supply and exhaust opening from which outside air flowing through a cooler is introduced.